SUSTAINABLE development: what does it mean to you?

The UK government defines achieving sustainable development as "building a strong, stable and sustainable economy which provides prosperity and opportunity for all".

We are to do this "meeting the diverse needs of all people in existing and future communities, promoting personal well-being, social cohesion and inclusion and creating equal opportunities for all".

It suggests that we, and future generations, can have it all - equality, prosperity, our diverse needs met, and all without any sacrifice. Certainly no tough choices have to be made - and no difficult political decisions either.

In the real world, some very difficult choices WILL have to be made.

The world is getting warmer. Almost everyone accepts that this warming is a result of the emission of carbon dioxide into the atmosphere. But how realistic are our efforts to slow it down?

Wind turbines are springing up everywhere. But how much wind generation would be necessary to make a significant difference?

After making great efforts to use energy efficiently, our generating capacity by 2020 will need to be about 67.5 gigawatts, and how many turbines would we need to generate just 10% of this capacity?

The largest wind turbines were planned for Pool Hill, near Denby Dale. They would have had a capacity of three megawatts. And because the wind does not always blow, such turbines are only 35% effective, so we would need 6,429 to generate just 10% of our electricity.

These turbines will be concentrated in windy areas and Yorkshire might expect about 1,280 of them. But that would reduce our carbon emissions by only 10%.

All those wind turbines have to be connected to the national gird. Because they are scattered over the countryside, this mass of cables is, for many, even more visually intrusive than the turbines themselves. So people will, and do, object.

Choices have to be made and there will be losers. And, at best, wind generation will only be able to make a very small difference to the sustainability of our electricity generation.

The number of people travelling by air is rising fast and is expected to double by 2020.

Yorkshire and the Humber generated nine million one-way trips last year. But air transport puts 600m tonnes of carbon dioxide a year into the atmosphere worldwide.

That is the same as the total emissions from the UK. So what are we doing about it?

Expansion is planned and airport development continues as fast as the planning system allows. Of course, air travel is popular and 800,000 jobs depend upon it, so a choice is made. Even if we could manage to generate 10% of our energy needs from wind power the savings would be cancelled out four times over by the growth in air travel by 2020. Are our priorities correct?

There is talk of a world policy of convergence whereby high-polluting countries, such as the UK and USA, reduce their carbon emissions while others, such as China and India, increase theirs as their economies develop.

Suppose we put a target on all countries of five tons of carbon emissions per head per year. That is one quarter of the current US level and about half of our level.

Even if we could achieve such an ambitious target, then global emissions would INCREASE by a third. The increases from India and China alone would exceed the total current emissions from the United States.

I am not arguing against energy savings or against the use of wind power, nor against recycling or any other environmental policy. We must, however, see them in perspective.

One cannot help but see some of the wind-turbine developments as more of an opportunity for landowners and energy companies to make money than anything to do with reducing global warming. Reducing air travel would have a much larger effect on carbon emissions. But both have costs. Wind power is opposed by many and a reduction in air travel would require big changes in lifestyle. Are we really committed to making a difference?

Whatever we do in this country will have only a small effect. A 10% reduction in our carbon emissions would reduce world emissions by just a quarter of one percent.

What happens in India, China and other populous countries trying to bring their people out of poverty, will be hugely more significant.

Would it not be better to spend the present subsidy we devote to wind power helping such countries fight poverty while using energy with the lowest possible carbon emission? Meanwhile, the world gets warmer.